Turkey vowed on Saturday that it would not allow any cover up in the Jamal Khashoggi case after Saudi Arabia admitted its operatives had killed the journalist but insisted that Mohammed bin Salman, the crown prince, was not involved. After more than two weeks of protesting its innocence, Saudi Arabia changed course and said that Mr Khashoggi, 59, died during “a fist fight” inside the Saudi consulate on October 2. The kingdom said it had arrested 18 Saudis in connection with the killing and sacked General Ahmed al-Assiri, the deputy intelligence chief, and Saud al-Qahtani, a close aide to Crown Prince Mohammed. Saudi officials insisted that the crown prince had no knowledge of the murder or subsequent cover up. King Salman tasked him with reforming the Saudi intelligence services, a sign that Crown Prince Mohammed's position remains secure. Donald Trump, the US president, said he found the explanation “credible” but the Saudi narrative was met with a wave of scepticism by American spy agencies and leading members of Congress. “To say that I am sceptical of the new Saudi narrative about Mr Khashoggi is an understatement,” said Lindsey Graham, a powerful Republican senator. Adam Schiff, the top Democrat on the House intelligence committee, said the explanation “is not at all credible”. The claim that Khashoggi was killed while brawling with 15 men dispatched from Saudi Arabia is not at all credible. If he was fighting with those sent to capture or kill him, it was for his life. The Kingdom must be held to account. If Administration doesn’t lead, Congress must.— Adam Schiff (@RepAdamSchiff) October 19, 2018 Omer Celik, a spokesman for Turkey’s ruling Justice and Development Party (AKP), said the country had “a debt of honour” to solve Mr Khashoggi’s death and would continue its own investigation. "Turkey will reveal whatever had happened. Nobody should ever doubt about it,” Mr Celik said. “We are not accusing anyone in advance but we don’t accept anything to remain covered [up].” His statement stopped short of saying Turkey did not believe the Saudi explanation but indicated that Turkish officials did not intend to immediately accept Riyadh’s version of events. Turkish police continue to search for Mr Khashoggi’s body. Saudi Arabia said that his killers handed the corpse to a local accomplice and that the kingdom did not know where it was. Turkish officials also claim to have gruesome audio tapes showing Mr Khashoggi was tortured before he was murdered and cut apart with a bone saw. The tapes, if confirmed, could undercut Saudi Arabia’s claim about a fist fight. Angela Merkel, the German chancellor, became the first major leader to say she did not accept the Saudi explanation of the "horrific events" in Istanbul. “They still haven’t been cleared up and of course we demand that they be cleared up,” she said on Saturday. The Saudi government has been under days of intense pressure to explain what happened to the dissident journalist after he entered the consulate more than two weeks ago. Jamal Khashoggi death | The unanswered questions Saudi officials said that the kingdom had issued a general order for Saudi dissidents to return home but that Gen Assiri had acted on his own to plan an operation to capture Mr Khashoggi in Turkey. "There were no orders for them to kill him or even specifically kidnap him," a Saudi official said. “[Crown Prince Mohammed] had no knowledge of this specific operation and certainly did not order a kidnapping or murder of anybody. He will have been aware of the general instruction to tell people to come back.” In the Saudi explanation, the 15-man squad confronted Mr Khashoggi when he entered the consulate and a fight broke out, resulting in the journalist's death. A Saudi statement said the interaction between Mr Khashoggi and his kidnappers “did not go as required and developed in a negative way, led to a fight and a quarrel between some of them”. Mohammed bin Salman's reputation as a reformer has come under scrutiny amid questions over Khashoggi's death Credit: Francois Mori/AP All 15 men, mainly spies and soldiers, were arrested along with two consular staff and a driver. Saudi Arabia said the 18 would be tried in Saudi courts. Three other intelligence officials were also sacked. Bruce Riedel, a former CIA officer and director of the Intelligence Project at the Brookings Institute, said it was “ludicrous” to claim Saudi officials had mounted the elaborate operation without Crown Prince Mohammed’s knowledge. “If this is the best cover up they’re going to be able to put forward it’s not going to pass muster,” he said. Regional allies - including Egypt, Bahrain and the United Arab Emirates - issued statements in praise of the king. Critics of Saudi Arabia pointed to several tweets by Mr al-Qahtani as evidence that the crown prince was fully aware of what his aides were doing. Inside the House of Saud In one 2017 tweet, Mr al-Qahtani said he would never act on his own initiative and described himself as “a faithful executor” of the orders of the king and crown prince. On the same day he warned a Saudi dissident living in London that the “assassination file has been reopened”. After his sacking, Mr al-Qahtani tweeted his thanks to the king and the crown prince for the "great confidence" they put him in and said he would continue to be "a loyal servant". Mr Khashoggi's Turkish fiancée, Hatice Cengiz, tweeted in Arabic: "The heart grieves, the eye tears, and with your separation we are saddened, my dear Jamal," she said, also asking "#where is martyr Khashoggi's body?" Custodian of the Two Holy Mosques directs that a ministerial committee be formed under chairmanship of HRH Crown Prince to restructure the General Intelligence Presidency and modernize its regulations and define its powers precisely.#SPAGOV— SPAENG (@Spa_Eng) October 19, 2018 Saturday's announcements confirmed days of speculation that the royal family would blame Gen Assiri for Mr Khashoggi's death. The commander, who trained at Sandhurst, had only recently taken up the number two position in the Saudi intelligence community. It was not clear if he would face any judicial proceedings. Supporters of Saudi Arabia insisted that the dismissal of senior officials was proof that the kingdom was not engaging in a cover up to protect the crown prince. "This is unprecedented," said Ali Shihabi, founder of the pro-Saudi Arabia foundation. The removal of two top officials, a cabinet ranking, very powerful and close advisor of MBS and the Deputy Head of Foreign intelligence + 4 other Generals in foreign intelligence (virtually its whole top leadership) cannot be written off as a cover up. This is unprecedented.— Ali Shihabi (@aliShihabi) October 19, 2018 Antonio Guterres, UN secretary-general, is "deeply troubled" by the admission, said a spokesman. The UN chief called for a "prompt, thorough, transparent" probe into the circumstances of Khashoggi's death and urged full accountability for those who were involved. The alleged killing has sent shockwaves through the world, dwarfing outrage over the kingdom’s recent arrest of women’s rights activists and its involvement in the deaths of civilians in the war in Yemen. The disappearance of Jamal Khashoggi In the past few days, foreign diplomats have suspended scheduled visits to the kingdom and more than two dozen senior officials and executives from the US and Europe have cancelled plans to attend the Future Investment Initiative, dubbed the “Davos of the Desert”. The announcement that Mr Khashoggi was killed at the consulate will heap more pressure on Britain to act against Saudi Arabia. Foreign Secretary Jeremy Hunt is considering the "next steps" in Britain's response to the case, officials said. Mr Hunt had earlier warned there would be "consequences" for the UK's relationship with Saudi Arabia if it was found the journalist was murdered.